Haptic operating device and method

ABSTRACT

A haptic operating device has a base, a stationary central part connected thereto, a rotary knob which can be rotated about the stationary central part and which has a hollow design, and a magnetorheological transmission device for influencing the rotational movement of the rotary knob in a controlled manner. The transmission device has two components which can be rotated relative to each other and one component of which is designed as a brake component that can be rotated relative to the base. The stationary central part is secured to the base by way of a support arm. The transmission device and the support arm are adjacent one another and both are received radially within the rotary knob. The rotary knob is rotationally fixed to the rotatable brake component via a coupling device.

The present invention relates to a haptic operating device comprising amagnetorheological transfer apparatus, and a method. The hapticoperating device according to the invention can be used in varioustechnical fields, for example for operating technical devices such asvehicles, aircraft, helicopters, watercraft or industrial installations,or for operating washing machines, kitchen appliances, radios, stillcameras, camera systems, mixing desks, light installations, hi-fiappliances, smart devices, laptops, PCs, smart watches or otherappliances.

Magnetorheological fluids have, for example, very fine ferromagneticparticles such as, e.g., carbonyl iron powder, distributed in an oil.Spherical particles with a diameter of 1 to 10 micrometers, saiddiameter being due to production processes, are used inmagnetorheological liquids, with the particle size not being uniform. Ifa magnetic field is applied to such a magnetorheological fluid, thecarbonyl iron particles of the magnetorheological fluid link along themagnetic field lines such that the rheological properties of themagnetorheological fluid (MRF) are significantly influenced as afunction of the form and strength of the magnetic field.

WO 2012/034697 A1 has disclosed a magnetorheological transfer apparatuscomprising two couplable components, the coupling intensity of which isable to be influenced. A channel with a magnetorheological medium isprovided for the purposes of influencing the coupling intensity. Amagnetic field is used to influence the magnetorheological medium in thechannel. Rotary bodies are provided in the channel, acute angled regionscontaining the magnetorheological medium being provided at said rotarybodies. The magnetic field of the magnetic field generating device isable to be applied to the channel, or at least to a part thereof, inorder to selectively link the particles and wedge these with the rotarybody or release these. This magnetorheological transfer apparatus canalso be used at a rotary knob for operating technical appliances. Such amagnetorheological transfer apparatus works and allows relatively highforces or torques to be transferred with, at the same time, a relativelysmall installed size. The entirety of the disclosure of WO 2012/034697A1 is incorporated in this application.

WO 2017/001696 A1 has disclosed a haptic operating device in which adisplay is disposed at an operating knob. The required power and datacables can be supplied to the display through a hollow shaft. To thisend, however, the bore in the hollow shaft must have a sufficientlylarge diameter. A further disadvantage of a hollow shaft is that theshaft must be sealed at both ends since the apparatus for influencingthe rotational movement in controlled fashion is disposed in theinterior. As a result of the seals at both ends of the shafts, thenumber of seals increases to two, as a result of which the base frictionincreases. A further disadvantage lies in the fact that there is agreater seal diameter and consequently a greater friction radius as aresult of the greater shaft diameter; this likewise increases the basetorque by a non-negligible amount. However, a particularly low basetorque is very advantageous in many applications, and often required sothat the required operating force remains low “in the idle state (basetorque)”. Otherwise, the operator may show symptoms of fatigue. Theentirety of the disclosure of WO 2017/001696 A1, too, is incorporated inthis application.

It is therefore the object of the present invention to provide a hapticoperating device with a magnetorheological transfer apparatus, by meansof which a base torque in the idle state that is as low as possible isfacilitated, with, in particular, a stationary central part beingprovided.

This object is achieved by a haptic operating device having the featuresof claim 1 and by the method having the features of claim 31. Preferreddevelopments of the invention are the subject matter of the dependentclaims. Further advantages and features of the present invention emergefrom the general description and the description of the exemplaryembodiments.

A haptic operating device according to the invention comprises a baseplate or main body, wherein such a base plate may also be embodied as aholder in preferred configurations. The haptic operating devicecomprises a stationary central part connected to the base plate and arotary knob with a hollow embodiment that is rotatable about thestationary central part and a magnetorheological transfer apparatus fortargeted influencing of a rotational movement of the rotary knob. Inparticular, the magnetorheological transfer apparatus brakes arotational movement of the rotary knob in a targeted fashion. The(magnetorheological) transfer apparatus comprises two components thatare rotatable relative to one another, one component of which isembodied as a brake component (also referred to as rotary component)that is rotatable relative to the base plate. The stationary centralpart is fastened to the base plate by a carrier arm (or two or morecarrier arms). The carrier arm is disposed adjacently to the transferapparatus. The carrier arm and the transfer apparatus are receivedradially within the rotary knob. The rotary knob is rotationallyconjointly coupled to the rotatable brake component by way of a couplingdevice.

In particular, the transfer apparatus is completely received in theinterior of the cavity of the rotary knob.

The haptic operating device according to the invention has manyadvantages. A significant advantage of the operating device according tothe invention consists of the standing central part facilitating thearrangement of a stationary user interface that does not co-rotate withthe rotary knob. The stationary central part is received radially withinthe rotary knob and adjacently to the transfer apparatus such that thestationary central part does not influence a rotational movement of thetransfer apparatus.

The transfer apparatus and the central part are preferably receivedadjacent to one another and/or next to one another and radially withinthe rotary knob.

Particularly preferably, the carrier arm and the transfer apparatus aredisposed next to one another. Therefore, the carrier arm is not disposedwithin the transfer apparatus but completely next to the latter. Thecarrier arm and the transfer apparatus do not penetrate one another.

The carrier arm and the transfer apparatus are preferably disposed inoff-centered fashion with respect to one another and/or in off-centeredfashion with respect to the rotary knob. This means that the axes ofsymmetry of the carrier arm and of the transfer apparatus are spacedapart from one another. Particularly preferably, the axes of symmetryare disposed radially within the rotary knob.

Preferably, the transfer apparatus is housed at least in part within thecavity of the rotary knob and, in particular, completely within saidcavity. The transfer apparatus and the central part are housed adjacentto an one another but not nested in one another. Influencing within themeaning of the present invention is understood to mean, in particular, abraking of the rotational movement of the rotary knob (brake torque).

In a simple configuration, another haptic operating device comprises arotary knob with a hollow embodiment and a magnetorheological transferapparatus for targeted influencing of a rotational movement of therotary knob and, in particular, for braking said rotational movement.Here, the rotary knob is rotationally conjointly coupled to the transferapparatus by way of a coupling device. The operating device may comprisea base plate, at which the magnetorheological transfer apparatus and thecoupling device are disposed and/or fastened.

A base plate is provided in a further haptic operating device accordingto the invention. Moreover, this haptic operating device comprises astationary central part and a rotary knob with a hollow embodiment thatis rotatable about the central part, and a magnetorheological transferapparatus for targeted influencing of a rotational movement of therotary knob. Within the rotary knob, the transfer apparatus is receivedwith a rotary component that is rotatable relative to the base plate andthe rotary knob is rotationally conjointly coupled to the transferapparatus by way of a coupling device.

In preferred configurations of all above-described operating devices,the rotary knob is rotationally conjointly coupled to the rotatablebrake component by the coupling device in such a way that a spatialalignment of the rotary knob and of the rotatable brake component withrespect to one another changes during the rotational movement of therotary knob. Here, a spatial alignment also comprises an orientation interms of angle such that different orientations in terms of angle arealso different spatial alignments within the meaning of the presentapplication.

Preferably, the coupling device comprises coupling means at the rotaryknob and the rotatable brake component. Even further coupling means maybe provided. By way of example, a further coupling means can beprovided, the latter being in contact with the coupling means at therotary knob on the one hand and being in contact with the coupling meansat the brake component on the other hand. It is also possible that useis made of even more coupling means, which then, overall, bring about acoupling of the rotary knob with the rotatable brake component.

By preference, the coupling device comprises teeth, gear wheels,friction surfaces, belts, chains, gears and/or planetary gears and thelike. In a simple configuration, the coupling device may be formed bytwo gear wheels or friction surfaces of friction wheels that are engagedin one another and bring about rotationally conjoint coupling.

Preferably, internal teeth are formed on an internal contour of therotary knob and external teeth coupled to the internal teeth are formedon an external contour of the rotatable brake component. The coupling ofthe rotary knob with the rotatable brake component can be implemented byway of a direct engagement or, for example, by way of a coupling meanssuch as a gear wheel or chain or the like.

Preferably, electrical cables are passed axially through the rotaryknob. The electrical cables may comprise connection cables for the powersupply, control cables and communication lines and more of same. Acombination of all these cable types is also possible, as a result ofwhich the passage opening must be correspondingly large. Possibly, aconnector (contact) fixedly connected to the cable must be implementedduring the assembly, requiring correspondingly large amounts of space.

In a preferred configuration, the central part comprises a carrier arm,the latter being connected (directly or indirectly) to the base plate atone end. Preferably, a carrier part is disposed at the other end of thecarrier arm. The carrier arm preferably extends axially through therotary knob. The carrier part can serve to carry various units anddevices.

Preferably, the carrier arm is disposed off-center in relation to therotary knob. In particular, the carrier arm (at least also) serves toguide the electrical cables. Electrical cables can be fastened to thecarrier arm. It is also possible for the electrical cables or for someof the electrical cables to be guided through the hollow carrier arm. Tothis end, the carrier arm preferably has a cavity or at least onecavity.

Preferably, at least one illumination unit is received in the carrierpart. Particularly preferably, at least one user interface is receivedin a carrier part. Such a user interface may comprise an operatingpanel, a display, a 3D display, a touch-sensitive display (touchdisplay) with or without haptic feedback and/or at least one sensor. Byway of example, a sensor such as a fingerprint sensor or a camera or thelike can be provided at the user interface in order to register andrecognize the fingerprint of a user. A visual camera, inter alia with acamera-based object recognition, can likewise be used to recognize theuser or user processes. An operating panel can be embodied as a touchpanel and can serve to input commands and gestures. The unit in thestanding central part can be activated and/or deactivated when the user(e.g., hand; finger) approaches or moves away.

The visual camera is also understood to mean machine vision or imageunderstanding, in general the computer-assisted solution to problemsoriented toward the capabilities of the human visual system. One processcan be a 3D object recognition for a more reliable recognition of 3Dobjects in the real surroundings (3D object recognition). Specifically,this relates to the detection of objects within a 3D point cloud which,inter alia, is recorded by lidar sensors.

This should not only recognize movements (gestures); on the contrary,said movements should also be associated with persons, and optimizedoperating patterns/operator guidance should be created therefrom. Usingthe example of a vehicle: if the operator hand is moved from left toright, this is a driver. If the hand comes from the right to left, thisis the front seat passenger (in the case of steering wheels disposed onthe left). The front seat passenger operates different menus andrequires different operator guidance to the driver of a vehicle.Moreover, the front seat passenger operates the operating element usingtheir left hand, which a right-handed person finds more difficult. Theoperating element can be set to accommodate this, for example by virtueof the switching torques or angle increments being increased as thisuser has less feeling or lower fine motor skills in the left hand. Thisis particularly advantageous if individual fingers are recognized andthe operation is adapted thereto.

Moreover, a visual camera can already recognize the person prior tooperation and can recall or associate operating patterns stored in thesystem. Thus, adolescents or children may be provided with differentoperating options (user guidance), menus, etc. when operating theoperating element than, e.g., adults. Thus, a pilot of an aircraft isimmediately assigned different operating patterns to a copilot.

It is also possible to recognize whether or not the user is wearinggloves. Both change the necessary haptic feedback for optimal userguidance.

The system is adaptive (e.g futty logic) and can be extensivelynetworked.

This greatly increases the operating quality and incorrect operationsare minimized.

In all configurations, it is preferable for the rotary knob and therotatable brake component to be separately rotatably mounted. Here, itis possible for the rotary knob and the brake component to be mounted byway of dedicated bearings such as sliding bearings or rolling bearings.However, it is also possible for the rotary knob and the rotatable brakecomponent to be rotatably received in corresponding low-friction guidesand consequently be mounted. In particular, the magnetorheologicaltransfer apparatus, which can also be referred to as brake device inpreferred configurations, is disposed within the rotary knob. Therotatable brake component and the rotary knob can be received nested inone another.

Preferably, one of the components of the transfer apparatus is formed asa stationary brake component. However, it is also conceivable that bothcomponents of the transfer apparatus each have a rotatableconfiguration.

Preferably, the stationary brake component is disposed radially on theinside and surrounded by the rotatable brake component. The rotatablebrake component may form a closed brake housing.

In particular, the stationary brake component comprises a shaft that isconnected to the base plate, the latter then being surrounded by therotatable brake component in particular. The shaft can have a thin andsolid embodiment and need not have a hollow embodiment. Preferably, nocables or lines are guided through the shaft.

By preference, the transfer apparatus has exactly one shaft output,which is sealed by way of exactly one contacting seal. In particular,the contacting seal is disposed between the rotatable brake componentand the stationary brake component. The contacting seal can be embodiedas a sealing ring and can be embodied, for example, as an O-ring, as alip-type seal, a wiper ring or as a quad-ring.

In preferred configurations, the transfer apparatus has the shaft outputon one side and a closed wall on the opposite side. Then, the rotatablebrake component overall forms a closed brake housing with a shaftoutput.

It is possible and preferable in all configurations for the rotary knobto have a substantially sleeve-shaped embodiment.

Preferably, the rotary knob comprises two tubular parts that are axiallydisplaceable with respect to one another, said tubular parts, inparticular, being rotationally conjointly coupled to one another by wayof coupling pins or guides or the like. In particular, the displaceabletubular parts are preloaded into the axially extended position by way ofa preloading device.

Preferably, the rotary knob or a tubular part is mounted to the baseplate by way of at least one bearing. In particular, the rotary knoband/or a tubular part of the rotary knob is axially displaceable(push/pull). Preferably, the rotary knob and/or a part of the rotaryknob is axially displaceable (push/pull or +/−Z) and provides hapticfeedback in the region of the end position. Other pressure functions mayalso be integrated into the rotary knob such that a signal is triggeredupon an axial actuation of the rotary knob and, in particular, hapticfeedback is provided in return. Pulling the knob (pull) is alsopossible. Likewise, the entire operating element can be additionallydisplaced to the side (X and Y direction/movement).

Preferably, at least one sensor for detecting an axial actuation in theform of, e.g., an actuation sensor and/or a sensor for detecting anangle change or an absolute angle position is associated with the rotaryknob.

It is preferable in all configurations for a difference between a clearinternal diameter of the rotary knob and an external diameter of thetransfer apparatus to be greater than 3 mm and less than 50 mm.Preferably, the difference lies between 10 mm and 30 mm.

In preferred configurations, an external diameter of the rotary knob isbetween 10 mm and 90 mm and and in particular between 20 mm and 90 mm. Aheight of the rotary knob is preferably between 10 mm and 60 mm.

It is preferable in all configurations for the transfer apparatus tocomprise a magnetic circuit and a magnetic field generating device withat least one electric coil and a gap between the stationary brakecomponent and the rotatable brake component, the gap or channel betweenthe two components of the transfer apparatus preferably being providedor equipped with a magnetorheological medium.

Particularly preferably, rotary bodies that serve in particular asmagnetic field concentrators are disposed between the stationary brakecomponent and the rotatable brake component or between the twocomponents of the transfer apparatus that are rotatable relative to oneanother. In particular, the rotary bodies are surrounded by themagnetorheological medium. The functionality of influencing therotational movement by way of rotary bodies in a gap or channel betweentwo components of a magnetorheological transfer apparatus is describedin WO 2012/034697 A1 and in WO 2017/001696 A1, and is used in a similarway or in the same way in a manner adapted to the structure presenthere.

A significant advance to the invention also consists of the fact thatthe base torque, low in any case, can be reduced even further sincethere is, regularly, a transformation of the rotational speed of therotary knob. In a specific configuration, the ratio is 3:1 and can,however, also become larger and reach or exceed 4:1, or else it can besmaller at 2:1. The effective base torque at the transfer apparatus isreduced accordingly as a result, which once again significantlycontributes to the ease of movement.

In a method according to the invention for targeted influencing and/orbraking of a rotational movement of a rotary knob with a stationarycentral part and an integrated angle sensor and an indirectly coupledtransfer apparatus and a display unit such as a display, the braketorque during the rotational movement of the rotary knob is modified asa function of the currently chosen menu (which is illustrated inparticular on a display unit) and/or a menu item (on the display unit).

Another method serves to set a haptic operating device and, inparticular, a smart appliance, wherein the method comprises:

-   -   providing a rotary element for manual actuation with a        stationary central part and a rotary part such as a rotary knob        with a hollow embodiment that is rotatable around the stationary        central part;    -   detecting a rotation of the rotary part during the manual        actuation thereof, a sensor such as a rotary encoder or an angle        sensor being used for the detection;    -   controlling an input of the haptic operating device (such as,        e.g., a smart appliance) according to the manual actuation of        the rotary element and setting a property of the rotary element        according to a currently selected menu of the haptic operating        device or the smart appliance.

Further advantages and features of the present invention arise from theexemplary embodiments, which are explained below with reference to theattached drawing.

In the drawing:

FIG. 1 shows a schematic perspective exploded view of a haptic operatingdevice according to the invention;

FIG. 2 shows a side view of the exploded view of the haptic operatingdevice according to FIG. 1;

FIG. 3 shows a haptic operating device according to the presentinvention;

FIG. 4 shows a very schematic cross section through a rotary body of ahaptic operating device according to FIGS. 1-3;

FIG. 5 shows a cross section through a haptic operating device;

FIG. 6 shows a very schematic cut plan view of a haptic operatingdevice;

FIG. 7 shows a further cross section through a haptic operating device;

FIGS. 8-10 show schematic cut plan views of further haptic operatingdevices;

FIG. 11a-11c shows possible torque profiles against the rotational angleof a haptic operating device according to the invention; and

FIG. 12 shows a cross section through one part of a further hapticoperating device.

FIG. 1 shows a schematic perspective exploded view of a haptic operatingdevice 200 according to the invention, which comprises a main body 210or base plate 210. The receptacle 210 a can have an integral embodimentwith the base plate or else it can be embodied as a separate part; itserves to receive the magnetorheological transfer apparatus 1.

Here, the magnetorheological transfer apparatus 1 comprises a rotatablebrake component 3, which is formed by the principal part of therotatable brake component 3 and the lower part 3 a. During the assembly,the two parts 3, 3 a are pressed together and consequently form a closedhousing or the rotatable brake component 3 overall. Received in therotatable brake component 3 is the stationary brake component orcomponent 2, which is guided out of the rotatable component 3 via astationary shaft 212. The stationary shaft 212 is fastened to the baseplate 210 or to the receptacle 210 a. By way of example, the shaft canbe screwed to the receptacle 210 a or the base plate 210 by way of ascrew such that the shaft 212, and hence the stationary brake component2, is securely received at the base plate 210. The rotatable brakecomponent 3 and/or 3 a is rotatably received in relation to the baseplate 210 or the receptacle 210 a by way of a rolling bearing 30. Aprotective sleeve 287 made of a hard or hardened or coated (e.g., hardchrome coating) material is pushed over the shaft 212 consisting of amagnetically conductive material during the assembly. The seal 46 in thepart 3 a acts on the protective sleeve 287 such that no grooves arise onthe stationary shaft 212, even during operation.

The rotatable brake component 3 or the upper part thereof has externalteeth 272 on the external circumference, said external teeth meshingwith the internal teeth 271 of the rotary knob 202 in the assembledstate. As a result, a rotational movement of the rotary knob 202 istransferred to the rotatable brake component 3.

Here, the rotary knob 202 substantially consists of two parts,specifically an upper tubular part 281 and a lower tubular part 282, inwhich the inner teeth 271 are formed in this case.

The two tubular parts 281 and 282 are rotatably conjointly connected toone another. By way of example, this can be implemented by way ofcoupling pins 283, which are inserted in corresponding receptacles inthe tubular parts 281 and 282. Springs 284 can be inserted into thecoupling pins 283, said springs consequently preloading the tubularparts 281, 282 into a base position where they are axially spaced apartfrom one another. Instead of the coupling pins, which engage in pores,use can also be made of linear guides (recirculating ball guides, linearball guides, profile guides . . . ).

The stationary central part 260 is disposed in the interior cavity 261of the rotary knob 202 and connected to the base plate 210. The standingcentral part 260 comprises a carrier arm 263, which extends from thebase plate 210 at one end to the upper end at which a carrier part 264is formed. The carrier part 264 serves to carry the circuit board 280and the illumination unit 266 disposed thereon. Here, the user interface267 is disposed at the top; said user interface may provide an operatingpanel of the haptic operating device. By way of example, the operatingpanel can also be embodied as a display or as a touch sensitive display.

FIG. 2 shows a side view of the haptic operating device 200 from FIG. 1in an exploded view. The rotatable brake component 3 comprises a lowerpart 3 a and the upper part 3 b, which both overall are referred to asrotatable component 3 and which receive the stationary brake component 2therein. Moreover, the rotary bodies 11 and the coil 26 including a coilholder 26 a are received in the interior of the rotatable brakecomponent 3. The remainder of the cavity is filled by amagnetorheological medium 6 (cf., FIG. 4). The shaft 212 is sealed tothe outside by the seal 46, the latter interacting with the protectivesleeve 287 that is applied to the shaft 212.

When put together, the tubular parts 281 and 282 yield the rotary knob202, which has an embodiment with a hollow interior and which is formedin a sleeve-like manner. This means that the rotary knob 202 has arespectively open embodiment both at the upper and at the lower axialend and has no wall. At the upper axial end, and consequently at the enddistant from the base plate 210, the haptic operating device 200 iscompleted by the operating panel 268, which, in particular, has atouch-sensitive or pressure-sensitive embodiment.

FIG. 3 shows a perspective illustration of an exemplary embodiment of ahaptic operating device 200, as illustrated in an exploded view in FIGS.1 and 2. The base plate 210 can have embodiments of different lengthsand different forms. In the illustration according to FIG. 3, the hapticoperating device 200 is suitable to be received hovering above thebackground. By way of example, the rotary knob 202 with the userinterface 267 can be illuminated by an illumination unit 266. By way ofexample, a sensor 275 can be integrated on the surface. It is alsopossible that the surface of the user interface 267 is suitable, overallor in part, for recording images, for example, such that, e.g., afingerprint can be recorded and recognized by the haptic operatingdevice 200 following contact with a finger.

FIG. 4 shows a very schematic cross-sectional view of amagnetorheological transfer apparatus 1 according to the invention, forinfluencing the force transfer between two components 2 and 3. Here, arotary body 11 is provided as a separate part 4 between the twocomponents 2 and 3 in FIG. 4. Here, the rotary body 11 is embodied as asphere 14. However, it is likewise possible to embody rotary bodies 11as cylinders or as ellipsoids, as rollers or as any other rotatablerotary bodies. Even rotary bodies that are not rotationally symmetric inthe true sense, such as, e.g., a gear wheel or a rotary body 11 with aspecific surface structure, can be used as a rotary body. The rotarybodies 11 are used not to bear one another but, instead, to transfertorque.

A channel 5, filled with a medium 6 in this case, is provided betweenthe components 2 and 3 of the magnetorheological transfer apparatus 1.Here, the medium is a magnetorheological fluid 20, which, e.g.,comprises an oil as a carrier liquid, in which ferromagnetic particles19 are present. Glycol, fat or viscous substances may also be used as acarrier medium, without being restricted thereto. The carrier medium mayalso be gaseous or the carrier medium can be dispensed with (vacuum). Inthis case, only particles that are able to be influenced by the magneticfield are filled into the channel.

The ferromagnetic particles 19 are preferably a carbonyl iron powder,the size distribution of the particles depending on the specific use. Aparticle size distribution of between one and ten micrometers isspecifically preferred, with, however, larger particles of twenty,thirty, forty and fifty micrometers also being possible. Depending onthe application, the particle size can also become significantly largerand even penetrate into the millimeter range (particle spheres). Theparticles may also have a special coating/cladding (titanium coating,ceramic, carbon cladding, etc.) so that they better endure the highpressure loads occurring depending on the application. The MR particlesfor this application case can be produced not only from carbonyl ironpowder (pure iron) but also, e.g., from specific iron (harder steel).

The rotary body 11 is made to rotate about its axis of rotation 12 as aresult of the relative movement 17 between the two components 2 and 3and practically runs along the surface of the component 3. At the sametime, the rotary body 11 runs along the surface of the other component 2such that a relative speed 18 is present there.

Strictly speaking, the rotary body 11 is not in direct contact with thesurface of the component 2 and/or 3 and therefore does not roll directlythereon. The clear distance 9 from the rotary body 11 to one of thesurfaces of the component 2 or 3 is 140 μm, for example. In a specificconfiguration of particle sizes between 1 μm and 10 μm, the cleardistance lies, in particular, between 75 μm and 300 μm and, particularlypreferably, between 100 μm and 200 μm.

In particular, the clear distance 9 is at least ten times the diameterof the typical mean particle diameter. Preferably, the clear distance 9is at least ten times the size of a largest typical particle. On accountof the lacking direct contact, a very low base friction/base force/basetorque arises during the relative movement of the components 2 and 3with respect to one another.

If a magnetic field is applied to the magnetorheological transferapparatus 1, field lines are formed depending on the distance betweenthe rotary bodies 11 and the components 2, 3. The rotary body consistsof the ferromagnetic material and, e.g., of ST 37 (S235) in this case.The steel type ST 37 has a magnetic permeability pr of approximately2000. The field lines pass through the rotary body and concentrate inthe rotary body. A high flux density in the channel 5 prevails at theentry and exit face, radial in this case, of the field lines at therotary body. The field that is inhomogeneous and strong there leads tolocal and pronounced linking of the magnetically polarizable particles19. As a result of the rotational movement of the rotary body 11 in thedirection of the wedge that is forming in the magnetorheological fluid,the effect is greatly increased and the possible brake or couplingtorque is magnified to the extreme, far beyond the value that isnormally generable in the magnetorheological fluid. Preferably, rotarybodies 11 and component 2, 3 consist at least in part of ferromagneticmaterial, which is why the magnetic flux density becomes ever higher thesmaller the distance is between rotary body 11 and component 2, 3. As aresult, a substantially wedge-shaped region 16 forms in the medium, thegradient of the magnetic field in said wedge increasing strongly to theacute angle at the contact point or the region of smallest distance.

Despite the distance between rotary body 11 and component 2, 3, therotary body 11 can be put into rotational movement by the relative speedof the surfaces with respect to one another. The rotational movement ispossible both without and with an acting a magnetic field 8.

When the magnetorheological transfer apparatus 1 is exposed to amagnetic field 8 of a magnetic field generating device 7 that is notillustrated here in FIG. 4, the individual particles 19 of themagnetorheological fluid 20 link along the field lines of the magneticfield 8. It should be noted that the vectors, plotted in FIG. 4, onlyvery schematically represent the region of the field lines that isrelevant to influencing the MRF 20. The field lines enter the channel 5substantially perpendicular to the surfaces of the ferromagneticcomponents and need not extend in a straight line, especially in theacute angled region 10.

At the same time, some material of the magnetorheological fluid 20 isalso put into rotation at the circumference of the rotary body 11 suchthat an acute angled region 10 forms between the component 3 and therotary body 11. An equal acute angled region 10 arises between therotary body 11 and the component 2 on the other side. By way of example,in the case of rotary bodies 11 configured in a cylindrical fashion, theacute angled regions 10 may have a wedge shape 16. The further rotationof the rotary body 11 is impeded by the wedge shape 16, and so theeffect of the magnetic field on the magnetorheological fluid isincreased since greater cohesion of the medium 6 arises within the acuteangled region 10 as a result of the magnetic field acting there. Asresult, the effect of the magnetorheological fluid is amplified in theaccumulated pile (the link formation in the fluid and hence the cohesionor the viscosity), making the further rotation or movement of the rotarybody 11 more difficult.

Substantially greater forces or torques can be transferred by the wedgeform 16 than would be possible with a comparable structure that onlyuses shear movement without a wedge effect.

The forces that are transferable directly by the applied magnetic fieldonly represent a small portion of the forces transferable by theapparatus. The wedge formation and hence a mechanical forceamplification can be controlled by way of the magnetic field. Themechanical amplification of the magnetorheological effect can go so farthat the force transfer is even possible after an applied magnetic fieldhas been deactivated if the particles were wedged.

It was found that a significantly greater effect of a magnetic field 8of a given strength is obtained by the wedge effect of the acute angledregion 10. Here, the effect can be amplified multiple times. In onespecific case, influencing of the relative speed of two components 2 and3 with respect to one another that was approximately ten times strongerthan in the prior art in the case of MRF couplings was observed. Thepossible amplification depends on different factors. Optionally, it canbe amplified even further by a greater surface roughness of the rotarybodies 11. It is also possible for outwardly projecting protrusions tobe provided on the outer surface of the rotary bodies 11, which can leadto an even stronger wedge formation.

The wedge action or the wedge effect is distributed in areal fashion onthe rotary body 11 and the components 2 or 3.

FIG. 5 shows a cross section through an embodiment of a haptic operatingdevice 202. The haptic operating device 200 is assembled on a base plate210, which comprises a separate receptacle 210 a for themagnetorheological transfer apparatus 1 in this case. The transferapparatus 1 comprises two components 2, 3, wherein the component 2 isembodied as a stationary brake component and screwed to the receptacle210 a. In this case, the brake component 2 has an approximatelymushroom-shaped form and comprises the shaft 212 and accommodates in themushroom-shaped part the electrical coil 26 in a coil holder 26 a as amagnetic field generating device 7. The electrical coil 26 is woundaround the axis of symmetry of the stationary brake component 2.

The rotatable brake component 3 comprises an upper part and a lower part3 a, which are pressed together during the assembly. The plotted sealbetween the two parts of the rotatable brake component 3 serves to sealpossible gaps. It is also conceivable to extend the part 3 a upward andto provide it with the teeth. Then, the part 3 would be embodied as acover.

Rotary bodies 11, which are guided in corresponding receptacles of thestationary brake component 2 and the rotational brake component 3, arereceived in the rotatable brake component 3. The magnetic field 8 isplotted in exemplary fashion at one rotary body 11 and passes throughthe rotary body 11, with the rotary bodies 11 being embodied as spheres14 in this case. The spheres 14 are disposed in a gap 5, which is filledwith a magnetorheological medium and, in particular, with amagnetorheological fluid.

The rotary knob 202 has a larger internal diameter and, as visible inFIGS. 1 and 2, comprises internal teeth 271 on the internalcircumference, said internal teeth engaging with external teeth 272 ofthe rotatable brake component 3 on the left-hand side in this case.

As a result, a clear interstice arises in this case on the right-handside, the stationary central part 260 being disposed therein andextending from the base plate to above the rotatable brake component 3.Above the rotatable brake component 3, the stationary central part 260forms a carrier part 264, to which the illumination unit 266, the userinterface 267 and an operating panel 168 are applied.

The tubular parts 281 and 282 of the rotary knob 202 are coupled to oneanother by way of coupling pins 283 in this case. Springs 284 aredisposed in the hollow coupling pins 283, said springs preloading thetwo tubular parts in a base position axially spaced apart from oneanother.

The rotary knob 202 is mounted directly on the base plate 210 by way ofa rolling bearing 276. The transfer apparatus 1 or the rotatable brakecomponent 3 is rotatably mounted on the base plate 210 or on thereceptacle at 210 a by way of a bearing 30, which is likewise embodiedas a rolling bearing.

An angle sensor 206 detects an angular position of the rotary knob 202.An actuation sensor 204 is activated in the case of an axial actuationof the rotary knob 202, it not being possible to recognize saidactuation sensor here in FIG. 5.

FIG. 6 shows a schematic cross-section in a plan view, it being possiblein this case to recognize the diameters of different sizes of the rotaryknob 202 and of the transfer apparatus 1. The transfer apparatus 1 isrotationally conjointly coupled to the rotary knob 202 by way of acoupling device 270 such that a rotation of the rotary knob 202 isdirectly converted into a rotation of the transfer apparatus 1 or into arotation of the rotatable brake component 3 of the transfer apparatus 1.Here, the coupling device 270 comprises internal teeth 271 at the rotaryknob 202 and external teeth 272 at the rotatable brake component 3.Here, the clear space for the stationary central part 260 is alsorecognizable, said stationary central part consequently being able topass axially through the rotary knob 202 proceeding from the base plate,without impeding the rotational movement of the rotary knob or of therotatable brake component. Electrical cables 241 can be passed throughthe inner cavity 261 of the stationary central part 260 in order tosupply power to the user interface 267, the illumination unit 266 or theoperating panel 268 and in order to provide communication lines.

FIG. 7 shows a modified embodiment of the haptic operating device 200 ofFIG. 5, with the actuation sensor 204 also been plotted in this case. Incontrast to the exemplary embodiment according to FIG. 5, cylindrical orroller-shaped rotary bodies 11 are provided in the exemplary embodimentaccording to FIG. 7. The stationary brake component 2 can have a trepan(groove) in the region of the magnetic field transition to the rotarybodies 11. This groove may be empty or else contain a friction elementin the form of a rubber ring (O-ring; ring cord, rectangular ring . . .). This can achieve a forced rotation of the rotary bodies 11. Asdescribed in relation to FIG. 5, the teeth can also be a part of theball-mounted inner body 3 a in the embodiment according to FIG. 7 andcan be sealed by a cover.

Moreover, a permanent magnet 25 is plotted in exemplary fashion; it canprovide a permanent magnetic field. The magnetic field of the permanentmagnet 25 can be influenced by the magnetic field of the electric coil26 and can also be canceled in the case of appropriate polarity. It isalso possible that the permanent magnet 25 is set by electrical pulsesof the electrical coil 26.

FIG. 8 shows a schematic cross section in a plan view, wherein thehaptic operating device 200 in this case once again comprises a rotaryknob 202 and a transfer apparatus 1 with an external rotatable brakecomponent 3 and an inner stationary brake component 2. Electrical cables241 can be guided to the operating panel, not recognizable here, througha stationary central part 260. The maximum width available for thestationary central part 260 is a width that arises from a differencebetween the internal diameter 285 of the rotary knob 202 and theexternal diameter 286 of the transfer apparatus 1.

In the illustration according to FIG. 8, the coupling device 270 canalso be formed by friction surfaces on the outer surface of therotatable brake component 3 and the inner surface of the rotary knob202.

FIG. 9 shows a further variant, wherein the transfer apparatus 1 in thiscase has an outer rotatable brake component 3 again. The rotatable brakecomponent 3 is rotatable about the central axis of symmetry of thetransfer apparatus 1 and of the rotary knob 202. In this case, thecoupling device 270 comprises, e.g., a gear wheel 273 as a couplingmeans between the internal teeth of the rotary knob 202 and the externalteeth of the transfer apparatus 1. As a result, enough installationspace is also available for stationary central part 260.

FIG. 10 shows another variant, in which the coupling device 270comprises a belt 274 or a chain, by means of which the rotationalmovement is transferred from a central rotational shaft 202 a to therotatable brake component 3. In this configuration, the stationary brakecomponent 2 surrounds the rotatable brake component 3. In thisconfiguration, the rotary knob 202 can be covered by a transparent pane,for example, at which the the rotational shaft 202 a is attachedcentrally, the latter being guided into the inner cavity of the rotaryknob 202 through the operating panel 268, the belt 274 for coupling withthe transfer apparatus 1 being disposed in said inner cavity. Sufficientinstallation space for the stationary central part 260 also arises insuch a configuration. If use is made of capacitive or optical sensors,the user interface 267 can also be used for the input of data, even ifthe user interface 267 is covered by the e.g. transparent wall of therotary knob 202.

FIGS. 11a, 11b and 11c illustrate possible embodiment variants for thedynamically generated magnetic field or the dynamically produced braketorque as a function of the rotational angle. Very different braketorques can be generated depending on the menu selection. Examples ofmenus in the case of motor vehicles include: air-conditioning level;temperature to the left or right; seat adjustment; volume. An operatingmenu can be chosen by pressing or pulling the operating element.

Here, FIG. 11a shows a variant in which a left end stop 228 and a rightend stop 229 are generated. A high magnetic field or stop torque 238 isgenerated if the rotary knob 202 is rotated further, as a result ofwhich the rotary knob 202 puts up a high resistance against a rotationalmovement.

A first latching point 226, which corresponds to a first menu item 225,is provided directly next to the left end stop 228. Should the next menuitem be selected, the rotary knob 202 must be rotated clockwise. To thisend, the dynamically generated higher magnetic field or cogging torque239 or the frictional torque thereof must be overcome before the nextlatching point 226 is reached. In FIG. 11a , a magnetic field that isconstant in each case is generated for a certain angle range, in eachcase at the latching points 226 and at the regions lying therebetween,said magnetic field being substantially lower at the latching pointsthan in the regions lying therebetween and being once againsignificantly lower than at the stops 228, 229.

An angle spacing 237 between individual latching points is dynamicallymodifiable and adapted to the number of available latching points ormenu items.

FIG. 11b shows a variant in which the magnetic field does not increaseabruptly at the end stops 228, 229 but has a steep profile instead.Furthermore, ramp-like gradients of the magnetic field are provided onboth rotational sides of the latching points 226, as a result of whichthe rotational resistance increases in the corresponding rotationaldirections. Here, only three latching points 226 are made available bythe same operating device 200, the angle spacing 237 of said latchingpoints being greater than in the example according to FIG. 11 a.

FIG. 11c shows a variant in which a lower rotational resistance ispresent between the individual latching points 226 and in which arespectively elevated magnetic field 239 is only generated directlyadjacent to the latching points 226 in order to facilitate latching ofthe individual latching points 226 and, the same time, to provide only asmall rotational resistance between the individual latching points.

In principle, a mixture of the modes of operation and of the magneticfield curves of FIGS. 11a, 11b and 11c is also possible. By way ofexample, a correspondingly different setting of the magnetic field curvecan be implemented in different submenus. Preferably, the current andhence torque changes are harmonious (smooth transitions, rounded, . . .) such that a haptically good or comfortable operating feeling arises.

It is also possible in all cases that, e.g., in the case of a ripple(latching), switching is not carried out as previously between less andmore current with the polarity (i.e., for example, +0.2 to +0.8A=ripple), but, alternately, with a change in polarity, i.e., from +0.2to +0.8 A and then the next ripple with −0.2 A to −0.8 A and then thenext torque peak from +0.2 to +0.8 A, etc.

The preferably low-allow steel may keep a residual magnetic field. Thesteel is demagnetized (alternating field), preferably at regularintervals or when necessary.

If the rotary unit is not rotated, i.e., if the angle is constant, thecurrent is preferably continuously reduced over time. The current canalso be varied in speed-dependent fashion (angular speed of the rotaryunit).

FIG. 12 shows an alternative embodiment, the structure of whichsubstantially corresponds to the structure of FIGS. 5 and/or 7.

All that is illustrated is the transfer apparatus 1, which is disposedin the interior of a haptic operating device 202. The transfer apparatus1 is assembled on a separate receptacle 210 a. The transfer apparatus 1once again comprises two components 2, 3, with the component 2 beingembodied as a stationary brake component and screwed to the receptacle210 a by way of the screw 278. Here, the brake component 2 has anapproximately mushroom-shaped form and comprises the shaft 212 andreceives the electrical coil 26 in a coil holder in or at themushroom-shaped part. The electrical coil 26 is wound around the axis ofsymmetry of the stationary brake component 2.

The rotatable brake component 3 comprises an upper part or a cover 3 band a lower part 3 a, which are pressed together during the assembly. Aseal can serve between the two parts of the rotatable brake component 3to seal possible gaps. Here, the external teeth 272 are formed at the(lower) part 3 a. The part 3 b forms the cover.

Rotary bodies 11 are received in the rotatable brake component 3, saidrotary bodies being guided in corresponding receptacles of thestationary brake component 2 and the rotatable brake component 3. Themagnetic field 8 is plotted in exemplary fashion by way of two fieldlines at a rotary body 11 and passes through the rotary body 11, withthe rotary bodies 11 having a cylinder-shaped or roller-shapedembodiment in this case. The rotary bodies 11 are disposed in a gap thatis filled with a magnetorheological medium and, in particular, amagnetorheological fluid. Here, provision is made of a circumferentialgroove 2 a, which contributes to concentrating the field at the rotarybodies 11.

As result of the external teeth 272 being formed at the lower part 3 a,the magnetic field can be improved. Greater wall strengths (within thepredetermined installation volume) can be realized.

The component 3 is mounted in rotatable fashion in relation to thereceptacle by way of a rolling bearing 30. An angle sensor 206 (e.g., arotary encoder) serves to detect an angle position.

In this configuration, the teeth 272 are no longer part of the cover 3 bas in FIG. 7 but are formed at the part 3 a. As a result, a strongermagnetic field can be generated there and a higher brake torque can beobtained. Moreover, rollers are used (FIG. 5: balls; FIG. 6: rollers). Agroove or a puncture 2 a concentrates the magnetic field. The screw 3 cfor filling the unit is disposed centrally in the cover 3 b and providedwith a sealing ring.

The contact faces of the parts (14; 3 a; 2 . . . ) that generate thebrake torque can have a surface structure (roughness; fine pattern) inall configurations.

The haptic operating device may also contain at least one loudspeaker(sound source), a Bluetooth unit, WLAN, a radio module, a microphone ora vibration motor.

The stationary central part may contain the following, without beingrestricted thereto:

-   -   static part (e.g., manufacturer logo, background-illuminated        logo, . . . ). It is possible and preferable for the central        part not to have direct function in that case.    -   touchpad (with functions)    -   screen (LCD, OLED, quantum dot, E-ink, transparent display, . .        . )        -   active            -   color LCD (TFT)            -   OLED            -   fluorescent display            -   electroluminescent display            -   quantum dots            -   micro LED            -   transparent display        -   passive            -   monochrome LCD            -   reflective color LCD            -   eInk monochrome/color            -   split-flap display            -   flip-dot    -   touchscreen        -   resistive systems        -   surface-capacitive systems        -   projected-capacitive systems            -   inductive systems        -   SAW (surface acoustic wave)-“(sound) wave-controlled            systems”        -   optical systems (as a rule, infrared light grid in front of            the monitor)        -   dispersive signal technology systems    -   3D gesture touchpad    -   Similar to capacitive touch detection, the GestIC technology        uses the measurement of the electric field to recognize        gestures.        -   2D gesture recognition    -   hologram projector        -   projects a 3D object    -   ARS (augmented reality system)    -   This is understood to mean the computer-assisted augmentation of        the perception of reality.    -   camera        -   seat control        -   facial recognition    -   fingerprint        -   person identification (starting the vehicle . . . )    -   iris scanner        -   person identification    -   In the case of a pulse measuring device, an LED illuminates the        supported finger. The color of the reflected light changes        regularly as a result of the blood pumping through the arteries        in regular thrusts. A photodiode measures the changes in the        color and provides this information to the system, which        calculates the pulse frequency therefrom.        -   The actuator can provide various types of feedback in the            case of an elevated pulse    -   The proximity sensor/infrared sensor employs an infrared beam to        verify whether something approaches the haptic knob        -   power saving mode    -   The RGB sensor    -   consists of a photodiode with a color filter and measures the        intensity and also the color temperature of light sources. This        leads to the monitor being able to offer more contrast and also        better color saturation.    -   NFC (near field communication, abbreviation NFC) is an        international transmission standard based on RFID technology for        contactless exchange of data by way of electromagnetic induction        by means of loosely coupled coils over short distances of a few        centimeters and a data transfer rate of no more than 424 kBit/s.        -   release via an ID card        -   identification using a smartphone    -   The gas sensor    -   is used to measure the air quality inside. As a long-term-stable        metal oxide gas sensor with a plurality of sensor elements on a        chip, the SGP provides detailed data in respect of air quality.        -   breathalyzer        -   oxygen content→risk of fatigue    -   moisture sensor        -   measures moisture    -   An acoustic fingerprint (microphone) is a digital code        characterizing a sound or an audio recording taking into account        specific acoustic conditions.        -   Security feature    -   particulate matter sensors (PM 2.5)    -   Carbon dioxide sensors (CO2)

All these sensors can be linked to the vehicle or at least to an articleto be operated. Information generated by these sensors flows into theoptimization of the operation or is used to increase customer utility.

List of reference signs:  1 Transfer apparatus  2 Component, stationarybrake component  2a Groove  3 Component, rotatable brake component  3aPart of 3  3b Part of 3, cover  3c Closure  4 Separate part  5 Gap,channel  6 Medium  7 Magnetic field generating device  8 Field  9 Cleardistance  10 Acute angled region  11 Rotary body, rotatable transferelement  12 Axis of rotation  14 Sphere  15 Cylinder  16 Wedge shape  17Direction of the relative movement  18 Direction of the relativemovement  19 Magnetic particles  25 Permanent magnet  26 Coil  26a Coilholder  27 Control device  30 Bearing  46 Sealing ring 200 Operatingdevice 202 Rotary knob 204 Actuation sensor 206 Angle sensor 210 Baseplate 210a Receptacle 212 Shaft 226 Latching point 227 Rotationaldirection 228 End stop 229 End stop 237 Angle spacing 238 Stop torque239 Cogging torque 240 Base torque 241 Cable 260 Stationary central part261 Cavity in 202 262 Internal contour of 202 263 Carrier arm 264Carrier part 265 Cavity into 63 266 Illumination unit 267 User interface268 Operating panel 268a Display unit 270 Coupling device 271 (Internal)teeth 272 (External) teeth 273 Gear wheel 274 Belt, chain 275 Sensor 276Bearing of 202 277 Shaft output 278 Side 279 Side 280 Circuit board 281Tubular part 282 Tubular part 283 Coupling pin 284 Spring 285 Internaldiameter of 202 286 Diameter of 1 287 Protective sleeve

1-32. (canceled)
 33. A haptic operating device, comprising: a baseplate, a stationary central part connected to said base plate, and ahollow rotary knob rotatably mounted about said stationary central part;a magnetorheological transfer apparatus for targeted influencing of arotational movement of said rotary knob, said transfer apparatus havingtwo components that are rotatable relative to one another, a firstcomponent being a brake component that is rotatable relative to saidbase plate; said stationary central part being fastened to said baseplate by way of a carrier arm and said transfer apparatus and saidcarrier arm being disposed adjacent to one another and received radiallywithin said rotary knob; and a coupling device rotationally conjointlycoupling said rotary knob to said rotatable brake component.
 34. Theoperating device according to claim 33, wherein said rotary knob isrotationally conjointly coupled to said rotatable brake component bysaid coupling device in such a way that a spatial alignment of saidrotary knob and of said rotatable brake component with respect to oneanother changes during a rotational movement of said rotary knob. 35.The operating device according to claim 33, wherein said coupling devicecomprises coupling means at said rotary knob and said rotatable brakecomponent.
 36. The operating device according to claim 35, wherein saidcoupling device comprises one or more elements selected from the groupconsisting of teeth, gear wheels, friction surfaces, belts, chains,gears, and planetary gears.
 37. The operating device according to claim33, wherein internal teeth are formed on an internal contour of saidrotary knob and external teeth coupled to said internal teeth are formedon an external contour of said rotatable brake component.
 38. Theoperating device according to claim 33, which comprises electricalcables axially passing through said rotary knob.
 39. The operatingdevice according to claim 33, wherein said central part comprises acarrier arm having a first end connected to said base plate, and asecond end supporting a carrier part.
 40. The operating device accordingto claim 39, which comprises a user interface received at said carrierpart.
 41. The operating device according to claim 40, wherein said userinterface comprises one or more of an operating panel, a display, atouch-sensitive display with or without haptic feedback, and/or at leastone visual camera or a sensor.
 42. The operating device according toclaim 33, wherein said transfer apparatus has one side with a shaftoutput and an opposite side with a closed wall.
 43. The operating deviceaccording to claim 33, wherein said rotary knob comprises two tubularparts that are axially displaceable with respect to one another, saidtubular parts being rotationally conjointly coupled to one another byway of coupling pins.
 44. The operating device according to claim 33,wherein said rotary knob is axially displaceable.
 45. The operatingdevice according to claim 33, wherein said rotary knob is axiallydisplaceable and configured to provide haptic feedback at an endposition thereof.
 46. The operating device according to claim 33,further comprising at least one sensor associated with said rotary knobfor detecting at least one of an axial actuation, an angle change, or anabsolute angular position.
 47. The operating device according to claim33, wherein said transfer apparatus comprises a magnetic circuit and amagnetic field generating device with an electric coil, and wherein amagnetorheological medium is disposed in a gap formed between saidstationary brake component and said rotational brake component.
 48. Theoperating device according to claim 47, further comprising rotary bodiesthat are surrounded by the magnetorheological medium and that aredisposed between said stationary brake component and said rotationalbrake component.
 49. The operating device according to claim 47, furthercomprising a control device configured to cause a variable brakingeffect at said rotary knob by selectively energizing said electric coil.50. A haptic operating device, comprising: a rotary knob with a hollowembodiment and a magnetorheological transfer apparatus for braking arotational movement of the rotary knob in a targeted manner; said rotaryknob being rotationally conjointly coupled to said transfer apparatus byway of a coupling device.
 51. A method for adjusting a haptic operatingdevice, the method comprising: providing a rotary element for manualactuation with a stationary central part and a rotary part, the rotarypart being a hollow rotary knob rotatably mounted for rotation about thestationary central part; detecting a rotation of the rotary part duringthe manual actuation thereof; controlling an input of the hapticoperating device according to the manual actuation of the rotary elementand setting a property of the rotary element according to a currentlyselected menu of the haptic operating device.
 52. The method accordingto claim 51, which comprises detecting the rotation with a sensor beinga rotary encoder or an angle sensor.